Summary: Rationale: Hepatoid adenocarcinoma (HAC) is an extrahepatic primary tumor that expresses morphological features resembling hepatocellular carcinoma. This rare malignant tumor has been described in the gastrointestinal (GI) tract, the testes, the ovaries, and rarely, the lungs. Despite there being no standardized management protocol for this case with poor prognosis, the literature describes responses to treatment with cisplatin–etoposide chemotherapy. Objective: We present an updated review of all cases of HAC of the lung and the favorable results of a novel management method for this type of tumor. Results: A table including all the HAC of the lung cases on the electronic database PubMed since 1980 is compiled. Here we present a case of primary HAC of the lungs, initially managed with cisplatin–etoposide without favorable response to treatment. The immunohistochemical profile of the tumor allowed for the novel use of immunotherapy in the setting of primary lung HAC, with favorable response. Conclusion and outlook: The case presented here is of interest as it adopts a novel immunotherapeutic approach to HAC, yielding a promising outcome. This highlights the importance of molecular typing and immunohistochemical profiling in the diagnosis and management of non-small cell lung cancer.